Relationship between rectal findings of corpus luteum and whole milk progesterone levels in postpartum dairy cows

The reliability of clinical ovarian findings was assessed as an indicator of luteal function in primiparous dairy cows. The postpartum period of 103 cows following their first parturition was studied by thrice weekly rectal palpation of ovaries and whole milk progesterone assay from 1 week after parturition to the first insemination. The relationship between milk progesterone levels and 1101 ovarian findings was compared during the follicular phases, short luteal phases and during the early, mid and late thirds of normal luteal phases. The compatibility between elevated progesterone and palpable corpus luteum was 71%, and between low progesterone and lack of corpus luteum 77%. In 10% of all rectal examinations the finding was unspecified; i.e. the clinician could not differentiate between luteal and follicular activity. During the acyclic period prior to the initiation of luteal function, the proportion of false corpus luteum findings was 11%. The corpora lutea of the short oestrous cycles were more difficult to palpate than those of normal cycles. During early dioestrus the corpus luteum was significantly more difficult to palpate than during the rest of dioestrus. The percentage of unspecified findings was highest during early dioestrus.The paper discusses the reliability of rectal examination as a method of diagnosing cyclicity and of evaluating the responsiveness of a cow to prostaglandin treatment.     

现浇砼梁板模板早拆技术的应用

本文介绍了梁板模板早拆的技术原理及体系构造，推行模板早拆施工方法，可大大减少模板投入量。降低劳动强度，加速工程施工，大面积的推广使用，可获得显著经济效益。     

不同光周期条件下PhyB和ABA对不同苜蓿品种的秋眠性调控

短日照和低温是导致苜蓿秋眠的主要环境因子。本研究检测了3个不同秋眠型苜蓿在8,12和16 h光照光周期条件下叶片和顶芽中PhyB和ABA的含量,并探讨其对秋眠的影响机制。结果表明,1)和非秋眠苜蓿相比,秋眠苜蓿叶片中PhyB含量高,PhyB作为绿色植物主要光受体可能通过光周期调控或参与了苜蓿的秋眠;并且3个品种均是在8 h光照下PhyB合成量高,暗示长暗期利于其合成。2)和12,16 h光照相比,8 h处理顶芽和第一展开叶中ABA含量最高,显然短日照利于ABA的合成;8 h光照处理时,秋眠型苜蓿品种Vernal ABA含量分别比半秋眠型CW5 0 2和非秋眠型CUF1 0 1高2.1 2和2.0 3倍,1 2 h光照处理ABA含量Vernal比CW5 0 2和CUF1 0 1分别高3 6.2 4%和46.46%,但16 h光照处理ABA含量并不表现上述规律,说明8和12 h光照程度不同地为苜蓿创造了逆境效应,ABA可能是调控或诱导秋眠的激素。3)8 h光照下苜蓿秋眠特征明显,生长严重受抑,不开花;12 h光照下苜蓿秋眠特征比8 h光照处理轻,生长受抑但抑制程度低于8 h光照处理,不开花;16 h光照下3个品种生长、开花正常。可能是PhyB含量多寡程度不同地调控了光周期反应,进而影响了ABA合成,而ABA在不同光周期诱导下通过合成量不同调控了不同秋眠基因表达,诱发了秋眠。     

大型海藻羊栖菜对新月筒柱藻生长抑制作用研究

研究了羊栖菜藻体、干粉及乙醇提取物对新月筒柱藻生长的影响。结果显示:羊栖菜藻体、干粉和乙醇提取物皆可明显抑制新月筒柱藻的生长,羊栖菜粉末及乙醇提取物对新月筒柱藻的生长的抑制作用表现出较强的浓度-效应关系。72 h时,新月筒柱藻生长抑制率与羊栖菜干粉初始浓度间的关系可表达为y=-0.3801x2+1.1636x,新月筒柱藻生长抑制率与羊栖菜乙醇提取物初始浓度间的关系可表达为y=-0.1445x2+1.4279x。羊栖菜粉末浓度达到1.6 g/L时,新月筒柱藻在3 d内全部死亡;乙醇提取物浓度达0.8 g/L时,藻细胞在2 d内全部死亡。由于乙醇提取物溶液的浓度是以提取前干粉质量表示,因此同等质量的羊栖菜粉末经过乙醇提取后其对新月筒柱藻生长的抑制作用明显高于未经提取的羊栖菜粉末。在1.6 g/L的羊栖菜乙醇提取物作用下数小时后,新月筒柱藻细胞核破裂,并逐渐向两端分散,至24 h时,细胞膜模糊,界限不清,细胞严重萎缩并逐渐碎裂解体。研究亮点:本研究发现大型海藻羊栖菜对冷水性赤潮藻新月筒柱藻的生长具有克生作用,羊栖菜乙醇提取物能明显抑制新月筒柱藻的生长,并对其作用机理进行了初步探讨,为赤潮的生物防治提供理论基础,丰富了海洋化学生态学的研究内容。     

短侧枝挂果核桃优良品种选择

针对云南核桃产业发展中存在的品种混杂,良莠不齐,丰产性能差等问题,开展了核桃(Juglans sig-illata)优良品种的选育工作。经过对核桃各品种的挂果情况的调查研究和品质分析,选出龙佳核桃、宁香核桃2个良种。     

山东临沂地区杨树人工林密度及经济效益的研究*

密度在人工林集约栽培中是一个重要问题,一旦确定在林分整个生长过程中都起作用,对采伐年龄和产量影响很大。合理的密度应保证林木群体结构最大限度地利用空间,达到最高产量,同时还应注意到所培育木材的径级的价格。 本研究总结了短轮伐期集约栽培下各种密度杨树人工休的生长规律及产量;探索间伐是     

Seasonal and age effects on energy requirements in domestic short‐hair cats (Felis catus) in a temperate environment

There is little information known about the energy requirements of cats in temperature climates. Energy requirement of domestic short‐haired cats was determined using three groups of mixed gender – old kept outside (approximately 9.9 years of age; 4.8 kg; n = 9), young kept outside (approximately 3.1 years of age; 3.9 kg; n = 8) or young kept inside (approximately 3.1 years of age; 3.9 kg; n = 8). Cats were housed individually for 5 weeks during summer (18.5 ± 0.5 °C) and winter (8.5 ± 0.4 °C) and were fed a commercially available maintenance diet ad libitum. In both periods, energy expenditure was determined from the rates of ²H and ¹⁸O elimination for blood H₂O over a 12 day period, from a doubly labelled water bolus ²H₂O (0.7 g/kg BW) and H₂¹⁸O (0.13 g/kg BW) administered intravenously. During the summer period, macronutrient digestibility was determined. Older cats had a reduction (p < 0.05) in apparent digestibility of dry matter (approximately 9%), energy (approximately 8%) and protein (6%). There was a significant effect of age and season on energy intake and energy expenditure. While lean mass was affected by age and season, there was no effect of age or season on energy expenditure when expressed as a proportion of lean mass. Possible seasonal differences in nutrient digestibility may explain these results.     

短期NaHCO3胁迫对3种冷季型草坪草生理生态特征的影响

土壤盐渍化严重威胁草坪草的可持续发展,选育和种植耐盐草坪草可改良和利用大面积盐渍土壤。以3种冷季型草坪草黑麦草(Lolium perenne L.)、高羊茅(Festuca arundinacea L.)和早熟禾(Poa pratensis L.)为试验材料,采用盆栽法研究不同浓度NaHCO3胁迫(0,0.2%,0.4%,0.6%,0.8%,1.0%)对3种冷季型草坪草生理生态特征的影响。结果表明:不同浓度NaHCO3胁迫下3种冷季型草坪草草坪外观质量、叶片萎蔫系数、叶片相对含水量、叶片叶绿素含量和K+含量均随着NaHCO3浓度的增加而逐渐降低,且浓度越高,下降越明显;0.4%～1.0%NaHCO3胁迫降低了3种冷季型草坪草的地上部分和根系干重,且随着NaHCO3浓度的增加,生长受到胁迫的抑制程度显著增大,根系部分的受抑制程度比地上部分更明显;不同浓度NaHCO3胁迫下3种冷季型草坪草叶片相对电导率、脯氨酸含量、丙二醛含量和Na+含量随着NaHCO3胁迫浓度的升高呈上升趋势,且浓度越高上升越明显;NaHCO3浓度0.4%时,3种冷季型草坪草已受到伤害;黑麦草、高羊茅和早熟禾在不同浓度NaHCO3胁迫下的隶属函数平均值均表现为早熟禾黑麦草高羊茅,说明3种冷季型草坪草抗NaHCO3胁迫的能力均为早熟禾强于黑麦草和高羊茅。     

短链葡聚糖-姜黄素纳米乳液的制备及结构表征

利用短链葡聚糖(short glucan chains,SGC)的螺旋空间结构来包埋姜黄素(curcumin,CUR)。通过使用高剪切分散乳化机高速剪切溶液5 min,用纳米均质机在50 MPa压力下高压均质经剪切后的乳液2次制备成纳米乳液以提高其包埋率和载药量。XRD (x-ray diffraction)和TGA (thermogravimetric analysis)很好的验证了包合物的形成,通过TGA、SEM (scanning electron microscopy)、激光粒径分析仪等各种表征分析得出短链葡聚糖-姜黄素纳米乳液制备成功,所制得的乳液对姜黄素的包埋率和载药量都高于短链葡聚糖-姜黄素包合物,分别达到了71.11%和12.07%,说明制备成纳米乳液对姜黄素的包埋率和载药量都有了明显的提高。所制备的纳米乳液的粒径小于300 nm,粒径分布均一,Zeta电位观测表明所制得的乳液的稳定性有所提高。为提高食品及医药领域姜黄素的生物利用率提供了一定的参考意义。     

SCFAs对奶牛瘤胃上皮细胞Ca2+信号通路相关基因表达的影响

为探究短链脂肪酸(SCFAs)对奶牛瘤胃上皮细胞(BRECs)Ca~(2+)信号通路相关基因表达的影响,试验分为3个处理组,分别为野生型BRECs组,含20mmol/L SCFAs BRECs组,含20mmol/L SCFAs且通过CRISPR/Cas 9系统敲除GPR41基因的BRECs组,每个处理组3个重复,每组细胞均培养24h后,收集细胞提取总RNA,通过qRT-PCR对Ca~(2+)信号通路相关基因的mRNA表达量和细胞内Ca~(2+)浓度进行测定。结果表明,与野生型BRECs相比,添加20mmol/L SCFAs可极显著增加PLCB2的mRNA表达量(P0.01),显著增加IP3R1的mRNA表达量(P0.05),对PLCE1、PLCL1、PKCB和PKCG的mRNA表达量无显著差异(P0.05),可增加细胞内Ca~(2+)浓度但无显著差异(P0.05);敲除SCFAs的受体GPR41后,添加20 mmol/L SCFAs可显著降低IP3R1的mRNA表达量(P0.05),极显著上调PLCE1和PLCB2的mRNA表达量(P0.01),但对PLCL1、PKCB和PKCG的mRNA表达量无显著影响(P0.05),细胞内Ca~(2+)浓度有降低趋势但无显著差异(P0.05)。综上,SCFAs可以通过激活其受体GPR41来调控BRECs内Ca~(2+)信号通路中相关基因的表达和细胞内Ca~(2+)的释放。